Glucocorticoids Flashcards
The zona fasciculata secretes _______, primarily ______. The zona reticularis secretes _______, primarily, ______.
glucocorticoids
cortisol
androgens
DHEA
List functions of cortisol (4).
- control metabolism
- regulate carbohydrates
- repair tissues
- some immune function
______ regulates both secretion of glucocorticoids and androgens from the adrenal medulla.
ACTH
Where is ACTH produced?
anterior pituitary
What is the function of DHEA?
converted to testosterone in tissues
main source of estrogen in females
Cortisol and DHEA require ______ for their production.
steroid (cholesterol)
List the structures in the synthesis of cortisol in order. (6)
cholesterol –> pregnenolone –> progesterone –> 17a-hydroxyprogesterone –> 11-deoxycortisol –> cortisol
Where does cholesterol get converted to pregnenolone in synthesis of cortisol?
mitochondria
Where do the following steps in the synthesis of cortisol occur:
pregnenolone –> progesterone –> 17a-hydroxyprogesterone –> 11-deoxycortisol
smooth ER
What is the final step in cortisol production? Where does it occur?
11-deoxycortisol –> cortisol
location: mitochondria
What hormone is produced in the hypothalamus which causes release of ACTH and therefore cortisol + DHEA secretion?
CRH (corticotropic releasing hormone)
What in the hypothalamus produces CRH?
paraventricular nucleus
What main metabolic function does cortisol promote?
gluconeogenesis
Cortisol (stimulates/inhibits) diuresis and therefore (stimulates/inhibits) ADH release.
stimulates
inhibits
In terms of its cellular functions, cortisol is involved in the formation and actions of what structures?
catecholamines
Cortisol increases the loss of _______ through urine and feces.
calcium
(T/F) Cortisol promotes Na+ secretion and K+ retention.
False - opposite
Cortisol promotes (increased/decreased) gastric and pancreatic secretions and (increased/decreased) mucosa proliferation in the GI tract.
increased
decreased
(T/F) Cortisol has a strong inotropic effect on the heart’s ability to contract.
False - weak
Cortisol causes (vasodilation/vasoconstriction).
vasoconstriction
Chronic cortisol elevations can cause what 2 musculoskeletal abnormalities?
- muscle weakness/atrophy
- osteoporosis
(T/F) Cortisol can decrease the threshold for seizures and cause sleepiness.
True
Cortisol (strengthens/weakens) the immune system.
weakens (blocks TH2 response, increased TH1 + inhibit phagocytic cell migration)
DHEA has similar functions as the hormone _________.
testosterone
DHEA is a substrate for ______ production and development of ________ at puberty.
estrogen
secondary sex characteristics
List the 5 things treated with glucocorticoid drugs.
- glucocorticoid deficiency
- arthritis
- pruritis (itching)
- neoplasia
- autoimmune disease
What are the 3 classes of glucocorticoid drugs?
short-acting
intermediate-acting
long-acting
What are two specific and common glucocorticoid drugs?
prednisolone
dexamethasone
What is unique about the structure of prednisolone which increases its potency by 4 times?
double-bound at C1-2 position
________ at the 16 alpha position of dexamethasone decreases ________ activity.
methylation
mineralocorticoid
_________ at the 9 alpha position of dexamethasone increases _______ potency and decreases _______ activity.
fluorination
corticosteroid
mineralocorticoid
What two drugs are in the short-acting glucocorticoid drug class?
- hydrocortisone
- cortisone
What 4 drugs are in the intermediate-acting glucocorticoid drug class?
- prednisone
- prednisolone
- methylprednisolone
- triamcinolone
What 3 drugs are in the long-acting glucocorticoid drug class?
- paramethasone
- betamethasone
- dexamethasone
Term for decreased cortisol production due to problem with the enzyme, 21-hydroxylase.
CAH (congenital adrenal hyperplasia)
CAH is a disorder where there is decreased production of cortisol due to an issue with ________.
21-hydroxylase
Individuals with CAH have no 21-hydroxylase function, and therefore (high/low) aldosterone, (high/low) cortisol, and (high/low) ACTH and DHEA.
low
low
high
CAH patients have a (retention/loss) of ECF volume and (hypotension/hypertension).
loss
hypotension
What is the main cause of Cushing’s Disease?
tumors (pituitary or adrenal)
What are the 2 types of Cushing’s Disease? What percentage are patients diagnosed with each?
- Pituitary Dependent Hyperadrenocorticism (80%)
- Adrenal Dependent Hyperadrenocorticism (20%)
What is the most common clinical sign of Cushing’s Disease?
polydipsia & polyuria
Patients with Cushing’s Disease exhibit a(n) (increased/decreased) blood glucose.
increased
What can become enlarged in Cushing’s Disease?
liver/abdomen
What are the 2 ways to diagnose Cushing’s Disease?
- elevated cortisol (blood/urine)
- ACTH challenge
In an ACTH challenge test, patients have a(n) (increased/decreased) ability to be make cortisol which signifies their diagnosis.
increased
What drug inhibits adrenocortical steroid biosynthesis and therefore treats Cushing’s Disease?
trilostane/vetoryl
(T/F) Surgery is a treatment option for Cushing’s Disease.
True
If a Cushing’s patient is given prolonged glucocorticoid treatment, this can lead to _______ which is iatrogenic or doctor-caused.
Addison’s-like Disease (hypoadrenocorticism)
